1. Field of the Invention
The present invention relates generally to an apparatus for performing circular anastomosis of hollow tissue organs and more particularly to an anvil delivery system for use with the apparatus to facilitate introduction and manipulation of an anvil through hollow organ tissue.
2. Description of the Prior Art
Anastomosis is the surgical joining of separate hollow organ sections so that the sections intercommunicate with each other. Typically, the anastomosis procedure follows surgery in which a diseased or defective section of hollow tissue is removed and the remaining end sections are to be joined. Depending on the desired anastomosis procedure, the end sections may be joined by either circular, end-to-side or side-to-side organ reconstruction methods.
In a circular anastomosis procedure, the two ends of the organ sections are joined by means of a stapling instrument which drives a circular array of staples through the end sections and simultaneously cores any overlapping tissue to free the tubular passage.
Examples of instruments for performing circular anastomosis of hollow organs are described in U.S. Pat. Nos. 4,304,236, 4,379,457, 4,573,468, 4,576,167, 4,603,693, 4,646,745, 5,119,983 and 5,122,156. These instruments typically include an elongated shaft having a handle portion at a proximal end to actuate the instrument and a staple holding component disposed at a distal end. An anvil assembly including an anvil rod with attached anvil head is mounted to the distal end. Opposed end portions of the organs to be stapled are clamped between the anvil head and the staple holding component. The clamped tissue is stapled by driving one or more staples from the staple holding component so that the ends of the staples pass through the tissue and are clinched by the anvil head.
In some applications of the circular anastomosis procedure, the anvil rod with attached anvil head is mounted to the distal end of the shaft prior to insertion of the instrument into the tissue to be anastomosed. However, in other applications, it is preferable to utilize a detachable anvil rod which may be mounted to the instrument subsequent to positioning of the instrument and the anvil assembly within their respective tissue sections. In such instances, the stapling instrument and the anvil assembly are separately applied to the operative site. Each tissue section is then secured to their respective anvil or staple holding component by a purse string. The anvil assembly is mounted to the surgical instrument by inserting a mounting portion of the anvil rod within the distal end of the instrument so that a mounting mechanism within the instrument securely engages the rod. Preferably, preparation of the tissue sections to be joined and mounting of the anvil rod to the instrument are performed using minimally invasive surgical techniques, i.e., under laparoscopic guidance.
A particular difficulty concerning the aforedescribed approach to perform anastomosis of hollow body organs with a detachable anvil assembly, whether the anastomosis is performed laparoscopically or by conventional surgical techniques, concerns delivery and placement of the anvil assembly at the desired location within the hollow organ. This difficulty is attributed to, inter alia, the fact that the anvil assembly, particularly, the mounted anvil head, presents an obtrusive profile which engages the inner wall of the hollow organ during advancement therethrough. In some instances, the dimension of the anvil head is greater than the cross-sectional dimension of the hollow organ in which it must pass. Consequently, advancement of the anvil assembly through the hollow organ is impeded or possibly prevented. Furthermore, if surgery is being performed laparoscopically, difficulty with maneuvering the anvil assembly through the hollow organ may necessitate an abandonment of such laparoscopic approach and a conversion to a conventional laparotomy to complete the anastomosis.
Accordingly, the present invention is directed to an anvil rod and related applications, which rod and associated structures facilitate delivery of the rod through organ tissue and maneuvering of the rod about the operative site. The structure also facilitates use of the rod in endoscopic and laparoscopic procedures.